Strategy To Enhance Interfacial Properties: Preparation of Porous Polytetrafluoroethylene Fibers and the Adsorption of Initiators/Curing Agents

Polytetrafluoroethylene (PTFE) fibers exhibit high inertness and demonstrate limited interfacial bonding capabilities with other materials. To overcome this limitation, PTFE@ZnO fibers were developed by depositing the porous ZnO layer onto PTFE fibers via a hydrothermal reaction, and porous fibers were adsorbed curing agents or initiators. The interfacial shear strength (ILSS) of the composites demonstrated a significant improvement, particularly in the case of composites containing PTFE/initiator fibers, where the ILSS increased by 104.8% compared to PTFE alone (from 8.3 to 17.0 MPa). The digital image correlation (DIC) method revealed a more uniform stress distribution in the modified fiber composites at the point of fracture. Additionally, nanoscratch tests indicated a significant enhancement in the interfacial bonding between the modified fibers and the resin. The porous structures facilitated mechanical interlocking between the modified fibers and the resin. Furthermore, the presence of an adsorbed initiator/curing agent within the porous structure served as the initiation site for the free radical polymerization of vinyl ester resin 901, thereby enhancing the interfacial bonding between the modified fibers and the resin. The novel strategy presents a general and viable approach for the extensive modification of PTFE fibers, focusing on achieving exceptional interfacial bonding properties.